1. Field of the Invention
The present invention generally relates to the field of telecommunications, particularly telephone communications. More specifically, the invention concerns a method, and a related system implementing the method, for forwarding telephone calls towards a mobile (cellular) phone.
2. Description of the Related Art
Telephone communications have long been and still are an extremely important, not to say essential inter-personal communication means, in both private life and business.
The importance of enabling a person, such as an employee, communicating by phone has led almost all of the business organizations, operating in the most diverse fields, to set up office telephony infrastructures comprising Private Branch Exchange (PBX) networks including from a few to a very large number of extensions, thereby possibly each employee can have a personal telephone on his/her desk, and can thus be reached by external calls.
However, in recent years the mobility of the workforce has increased significantly, and in order to enable people doing at best their job even when they are out of the office, business organizations normally provide at least a part of their employees with mobile phones.
In order to let an employee be reached by a telephone call directed to him/her and received at the employer's PBX, the most trivial solution is that an operator at the PBX switchboard, receiving and answering the external call, firstly forwards the call to the correct PBX extension and, in case of no response, informs of this the calling person and provides thereto the employee's mobile phone number, thereby the calling person can directly try to call the desired person over the mobile phone.
Clearly, this way of doing is unsatisfactory under several respects. Firstly, it implies that the mobile phone number of the employee be revealed, which is something highly undesirable, for reasons of privacy. Secondly, the calling person has to place two calls, which may result annoying, at least for reasons of costs.
A better solution is to forward the incoming telephone call to the employee's mobile phone.
Forwarding of telephone calls (shortly, call forwarding) is a feature commonly made available by almost all of the telephone companies, and even by specialized PBXS. When enabled, this feature allows re-directing calls originally directed to a telephone number towards another telephone number, specified by the user.
Call forwarding is probably better known in wire-lined, i.e. fixed telephone networks, but several solutions have been proposed that exploit call forwarding for enabling employees that are out of the office to be reached on their mobile phones.
An exemplary solution is provided in the U.S. Pat. No. 5,839,067, whose basic concern is however to allow a company/organization controlling all outgoing calls from its mobile telephones, so as to avoid overbilling due to more or less fraudulent use thereof for private purposes. In that document, a corporate/organization communications system is described including a mobility server service node connected to the company/organization's PABX, managing calls to and from corporate/organization's mobile phones. When a PABX external subscriber makes a call to an employee who is out of the office, the PABX, after having established that the employee is out, routes the call to the mobility server, which parks the call and notifies the called employee by making an outgoing call to the employee's mobile phone. The called employee, once notified, makes an outgoing call to the mobility server using the home PABX number and, when asked for the destination of the call, he/she dials a predefined code, thereby the PABX interconnects the call with the parked call.
Another exemplary solution of call forwarding is provided in the United States patent application US 2002/0019242 A1, describing a method and apparatus for communicating via virtual office telephone extensions. A wireless connect unit, in communication with an enterprise's PBX network, serves as a gateway between the PBX and remote communication devices including wireless devices, associated with a virtual extension telephone number. The remote wireless device can be used as a standard PBX office telephone for both inbound and outbound calls. When the system receives an incoming call, it can route the call to a remote wireless device associated with a virtual extension.
Still another example of call forwarding solution is provided in the United States patent application US 2002/0132638 A1, that describes a mobile branch exchange (MBX) allowing a mobile phone user to exploit the functionality of a PBX as if he/she were using a PBX-connected wire line phone in an office setting. An incoming call from a remote telephone arriving at the PBX is routed to the office telephone associated with the telephone number dialed. The MBX is notified of the call, and two processes are initiated: first, the MBX sets up a phantom call between a virtual terminal associated with a phantom PBX number and the mobile phone, via the GSM network; second, a data path is established between the MBX and the mobile phone, whereby the mobile phone user can apprise of who the caller is. If the mobile phone user decides to answer, the virtual terminal holds the phantom call and places a new call to the office telephone, and the phantom call and the new call are conferenced together. Then, the new call is answered and placed in hold, the incoming call is answered, and the new call is transferred, whereby the end effect is to merge the phantom call and the incoming call, and remove the office telephone from the call. In this way, the MBX causes the PBX to automatically connect a remote caller, who dialed an office telephone number, to a mobile telephone user, without the remote caller even knowing that the mobile telephone user is not actually answering the call from his/her office telephone.
Forwarding of telephone calls received at a wire-line telephone line associated with a PBX is also at the base of U.S. Pat. No. 6,141,545, which however describes a method and a system by means of which a subscriber to a remote call forwarding feature on the wire-lined telephone can enable the call forwarding remotely, by dialing a feature code from his/her cellular phone.
The Applicant observes that the phone call forwarding methods and systems briefly discussed in the foregoing, although satisfactory under many respects, share however a common drawback that, according to the Applicant's perception, may significantly limit their widespread diffusion.
Exception made for very special cases such as toll-free numbers or, at least partially, in international roaming contexts, when a caller makes a telephone call to another person the cost of the call is normally sustained by the caller, not by the called. In the call forwarding methods and systems known in the art, instead, when an external telephone call arriving at the PBX, or at an extension thereof, is forwarded to the mobile phone of the employee, the cost of the call from the PBX to the employee's mobile phone is sustained by the employer, the calling person only sustaining the cost of a normal, PSTN call, that is a call to a fixed, non-mobile telephone number. This causes an extra-cost for the employer's organization. Many enterprises/companies might for this reason decide not to implement this call forwarding capability, thus greatly limiting the possibilities of intercommunications for their employees.